The invention concerns an injection device for the combustion chamber of a turbine engine and in particular a device linking the fuel intake manifold with the injector head.
The development of the performance of advanced engines rests to a great extent on increasing the compression rate and the temperature ahead of the turbine.
This imposes certain requirements at the level of the combustion chamber and in particular in relation to the placement of the injector head in the bottom of the chamber. This placement must be relatively accurate in order to obtain the homogeneous atomization of the fuel inside the chamber and uniform combustion. The injector head must therefore follow the chamber in its displacements of thermal and mechanical origin.
FR No. 2,193,141 proposes a solution consisting of mounting the injector head on the combustion chamber and passing the fuel through tubing, the end of which carries the spraying nozzle and terminates in the axis of the head, without contact with said head. The tubing is held only by its fastening to the wall of the chamber. This device, while well suited to engines of the preceding generation, is no longer adequate for the new engines, such as those defined hereinabove, wherein the distance between the fuel intake manifold and the combustion chamber is large and does allow for the sufficiently rigid mounting of the fuel line.
FR No. 1,535,882 describes a device wherein the fuel tubing is supported at its two ends: on the combustion chamber and on the outer casing. The axes of the chamber and the tubing are identical, which permits neglecting radial expansions and eliminates the need for correcting longitudinal expansions. The fuel line tubing is formed by coaxial tubular elements wherein the liquid and gaseous fuel circulate. The differences in longitudinal expansion between the tubing and the chamber are compensated by means of a device with a spherical configuration provided between the tubing and the chamber and permitting their relative displacement.